It's never great when Wall Street believers lose the faith, and Monday brought a trio of notable downgrades that suggest analysts are getting more cautious about some previously favored names.

The headliner? Adobe Inc. (ADBE) got knocked down a peg by Jefferies analyst Brent Thill, who shifted his rating from Buy to Hold and chopped his price target from $500 down to $400. That's a significant haircut for a stock that closed Friday at $333.30, already well below where bulls thought it would be trading. When an analyst who was previously telling clients to buy the stock switches to "hold," it's worth paying attention.

Over in the pizza world, TD Cowen analyst Andrew M. Charles downgraded Domino's Pizza Inc. (DPZ) from Buy to Hold while trimming the price target from $500 to $460. Domino's shares closed at $425.28 on Friday, so there's still some implied upside in that new target, but the message is clear: Charles isn't as excited about the delivery giant's prospects as he used to be.

Rounding out Monday's downgrade parade, JP Morgan analyst Jimmy Bhullar moved Principal Financial Group Inc. (PFG) from Overweight to Neutral and set a $103 price target. With Principal Financial shares closing at $89.42 on Friday, that target suggests about 15% upside, but "Neutral" is analyst-speak for "we don't see enough reason to get excited here."

These rating changes matter because they reflect shifting expectations from analysts who follow these companies closely. When multiple high-profile names get downgraded on the same day, it's often a sign that the bar for these stocks has gotten harder to clear, whether due to valuation concerns, competitive pressures, or simply dimming growth prospects.